A. Field of the Invention
Techniques described herein relate generally to interactive voice response systems, and, more specifically, to improving speech recognition results in an interactive voice response system.
B. Description of the Related Art
Interactive voice response, or IVR, refers to a computerized system that allows a user, typically a telephone caller, to select an option from a voice menu or otherwise interface with a computer system. Generally, the system plays pre-recorded voice prompts to which the user responds by either pressing a number on a telephone keypad or speaking to the system.
In IVR systems that allow a user to interact verbally with the system, a speech recognition engine is used to attempt to automatically recognize what the person is trying to say. Speech recognition engines typically return two major components in response to an input speech utterance: (1) the textual transcription and/or semantic interpretation (also referred to as a “recognition result”) of the utterance; and (2) a confidence measure of the recognition result. The IVR system will typically compare the confidence measure with a predetermined threshold and only accept the recognition result if the confidence measure is above the threshold. An accurate confidence estimation and a properly set confidence rejection threshold can significantly improve the tradeoff between minimizing false acceptance (FA) of erroneous recognition results and maximizing correct acceptance (CA) of good recognition results.